Pump output regulator



Nov. 23, 1948. J. MERCIER FUI? OUTPUT REGULATOR med June 1a. 194s s sheets-sheet 1 mvENtoR Jean Menzr Nov. 23, 1948. J. MERCIER PUIIP OUTPUT REGULATOR 5 Sheets-Sheet 2 Filed June 18. 194s vnmnmnen y11W/ uvre); Jean Mer'cr Bly AMJ J ATTORNEY Nav. 23,A 1948. :.MelizclEFz PUK? OUTPUT REGULATOR 3 Shoots-Shoot 5 Filed June 18, 1943 lY u l, e

. INVTOR.

Jean Mercr sy ATTORNEY Patented Novt. 23, 1948 7 Claims.

The present invention pertains to pumps in which a plurality of piston-cylinder systems is in reciprocating operation.

When pumps are usedf'on aircraft or vehicles to supply fluid under pressure to fluid actuated devices, lt is frequently inconvenient to make arrangements whereby such pmps can be started or stopped whenever supply of-iluid is or is not required. On the contrary, it is generally desired that the pump be driven continuously by the engine of the machine and that other means be base of each Acylinder and the head of the cor responding piston to force the piston out of its cylinder whenever the position of casing 2 per mits that movement.

The interior of casing I is intended to be filled with the fluid to be pumped.

During the intake stroke of each piston fluid may be drawn into the corresponding cylinder a cylinder I.

provided to make the pumping action ineffective whenever the required pressure is reached not withstanding the continued' driving of the pump. In addition, it is generally desired that the pump be driven under minimum load whenever no pumping action is required in order to save energy and avoid 4unnecessary wear of the pump. Y

To that end, it is a feature of the present invention that all fluid pressure is discharged from the cylinders into a common collecting chamber which communicates with the main delivery v port.

According to a further feature of the presentinvention, valve means are inserted into said collecting chamber and, whenever the pressure in the main delivery port exceeds a predetermined value, these valve means will divert the ow of fluid by establishing a' communication between delivering cylinders and intaking cylinders or between the former and an auxiiary delivery port from which a low pressure circuit may be supplied. cylinders may be placed successively or alternatingly in communication with both, the intaking cylinders and an auxiliary delivery port.

Further features may be gathered from .the following description of two embodiments of the present invention illustrated in the accompanying drawings.

In the drawings Fig. 1 is a plan view of a pump according to the present invention;

Fig. 2 is`a partial sectional view of the same pump taken along line 2-2 of Fig. 1;

Fig. 3 is a section-al view of a modified pump according to the present invention;

Fig. 4 is a section in a different plane of a detail of the pump according to Fig. 3;

Fig. 5 is an enlarged section of a modification of a detail of the pump according to Fig. 3.

In Fig. l four cylinders I are eccentricaly mounted in a cylindrical casing 2 on a cylinder block 3. Pistons 4 are associated with cylinders I and their heads contact the inner wall of casing 2 with the interposition of ball bearings 6 or the like.

When casing 2 is rotated two of the pistons are forced home into their respective cylinders while the two other pistons are free to perform the intake stroke. Spring 5 is provided between the Optionally, the discharging through an orifice 'I and a passage 8 extending axially throughout the piston and opening into y Checkvalve 9 prevents any back ilow of 'uid from cylinders I into casing 2.

The arrangements for the discharge of fluid compressed in the cylinders during the return stroke of the piston are shown in Fig. 2. Fluid entering casingl 2 through port III and flowing into cylinders I through passages 1 and 8 may leave the same through passages II, I2 or I3.

In order to control the flow of fluid through these passages a cylinder bore I4 is formed inV cylinder block 3 and a movable valve element I-5 is silidably engaging the wall of bore I4. Element I5 includes two annular recessed portions I6 and Il and an axial passage I8 connecting recessed portion I6 with the interior of bore I4 whichQin turn, communicates-wlth the outside.

Spring I9 tends to -force element I5 into its normal position (as shown) in which passages I2 and I3 are obstructed. All iluid present in cylinders I is, in this position of element I5, discharged through passages II, collected in cham- `ber 20. and leaves the pump through port 2| Vconnected to a utilization circuit. Check valves 22 prevent any back flow of fluids from chamber 20 into cylinders I. Since rotation of the housing 2 is about the axis of element I5, inlet port I0 will rotate but does not need to be attached to a fluid supply but preferably should be submerged in the reservoir or a sump supply.

Cylinder bore Il communicates with chamber 2D through opening 24. Thus, whenever the pressure in chamber 20 exceeds the strength` of spring I9 element I5 will be displaced in the direction of arrow a whereby first passages I3 will register with recessed portion IG and, in case of an extreme displacement of element I5, passages I2 will be placed Ainto communication with each other through recessed portions I1.

Communication between passages I3 through recessed portions I6 permits fluid, during approximately one half of the delivery stroke, to escape from one cylinder to another or through bore I4 to the outside. Thus, while the pistons may continue to reciprocate, only one half of the stroke wi'l be used for effective pumping action. It is obvious that the effective portion of the stroke can be varied at will by changingthe level at which passage 'I3 opens into cylinder I, Also, obviously, bore I4 instead of communicating with the outside may be connected to an auxiliary de- 3 livery port for feeding an auxiliary low pressure circuit.

The communication between passages I2 aords free flow of fluid between |both cylinders. Consequently, in the position of element I5 in which passages I2 register with the recessed portions I1 the reciprocating movement ofthe piston continues while all effective pumping action ceases.

In Fig. 3 a revolving head 32 is journalled in pump casing 3| carrying a swash plate 33. A plurality of cylinders 34 is arranged inside casing 3| in circular series around the longitudinal axis of the pump. A piston 35 is associated with each cylinder whose position is controlled by the contact between the piston head 36 and swash plate 33. Liquid is supplied to the pump through inlet port 31, conducted through the central portion of the pump to the center of swash plate 33 and, thence, forced to the periphery by the turbine effect engendered by the rotation of plate 33. Under the effect of the resulting pressure, it is accumulated in annular chamber 38 adjacent swash plate 33 and enters cylinders 34 through suitable 'conduit 39. Part of the fluid accumulated under pressure may be withdrawn through auxiliary delivery port (or ports) 38a adjacent chamber 38.

Whenever a, piston 35 is forced into cylinder 34 by the movement of plate 33, liquid will be expelled from the respective cylinder through passages 40 or 4I. Check valves 40a and 4Ia will prevent any Ibackflow of fluid into cylinder 34. All passages 40 open into a common collecting cham- -ber 42 provided in the pump casing and communicating with discharge port 43. The flow of fluid through passages 4I is controlled by a slide valve comprising a cylinder bore 44 and a movable valve element 45, slidably engaging the wall of bore 44. Element 45 is urged by spring 46 in the direction of arrow b and in the opposite direction by the pressure exerted on element 4`5 by the pressure prevailing in chamber 42. Whenever this pressure exceeds the strength of spring 46, element will be displaced so that annular recessed portion 41 of element 45 will communicate with passages 4 I.

Fig. 4 shows the communication of portion 41 with an auxiliary discharge port 448.

By virtue of this arrangement cylinders 34 will deliver fluid into port 48-which may be connected, for instance, to an auxiliary utilizzaition4 circuitwhenever the pressure in port 4'3-connected to the principal utilization circuitexceeds a predetermined value.

Optional alternatives of the structure as illustrated and described are to omit either check valves 4Ia alone or port 48 and the said valves, whereby part or all of the fluid from the delivering cylinders is divertedas long as element 45 opens passages 4`Ito .the intaklng cylinders.

It is advantageous to give chamber 42, bore 44 and element 45 relatively large dimensions and so to space portion 41 from passage 4I that chamber 42, bore 4'4 and element'45 will act as a hydraulic accumulator of sufllcient capacity to absorb the usual pulsations of pumps of that type before passages 4I are uncovered. By virtue of this arrangement the usual variations in the delivery of fluid from the cylinders will be compensated by slight movements of element 45. This structure insures a steady delivery under nearly constant pressure through port 43 while avoiding any premature reduction of the load due to bypassing of fluid through passage 4I and portion 41.

A detent 50 may be provided on a projection of element 45.

Fig. 5 shows an alternative arrangement of the'l pump shown in Fig. 3 in which annular recessed portion 41 is shorter in the axial -direction over a portion vof the periphery of element 45 corresponding to the opening (or openings) of one or more passages 4I into bore 44'.

This arrangement delays the pressure relief for one or more of the cylinders 34 while some of them are relieved as soon as element 45 begins to be displaced.

The foregoing description is not intended to limit the present invention which extends to all changes, modifications and equivalents within the scope of the appended claims. y

What is claimed is:

'1. A pump which comprises a pump casing, a plurality of cylinders inside said casing, alcheck valve ported piston associated with each said cylinder, means to cause-said pistons to reciprocate in sequence within said cylinders without themselves rotating, means to admit fluid through the center of 4said pistons to said cylinders, a collecting chamber communicating with all said cylinders and with a principal delivery port Within said casing, means to conduct fluid `delivered by said cylinders into said chamber, fluid receiving means within said casing. valve means within said chamber responsive to the fluid pressure within said principal delivery port, said valve means being adapted to divert fluid from said chamber into said receiving means whenever the plurality of non-rotatable cylinders inside saidv casing, a piston having a check valve in its head associated with each said cylinder, means to cause said pistons to reciprocate in sequence within said cylinders, means to admit fluid to saidcyiinders through said check valves, a collecting chamlber communicating with all said cylinders and with a principal delivery port Within said casing, means to'conduct fluid delivered by said cylinders into said chamber, valve means within said chamber responsive to the uid pressure within said principal delivery port, said valve means being adapted to afford communication between all said cylinders whenever the pressure in said principal delivery port exceeds a predetermined value.

3. A pump which comprises a pump casing, a plurality of non-rotatable cylinders inside said casing, a check valve ported .piston associated with each said cylinder, means to cause said pistons to reciprocate in sequence within said cylinders,

means to admit fluid to, said cylinders through said check valves, a collecting chamber communicating with all said cylinders and with a principal delivery port within said casing, means to conduct fluid delivered by said cylinders into said chamber, valve means within said chamber responsive to the fluid pressure within said principal delivery valves, a collecting chamber communicating with all said cylinders and with a principal delivery port within said casing,. means to conduct iluid delivered by said cylinder into said chamber, a cylinder bore inside said chamber,V a movable valve element slidably engaging the Wall of said cylinder bore, said movable valve element being subjected on one side to the pressure prevailing in said chamber, said pressure tending` to displace said valve element in one direction, and being subjected on the other side to resilient means tending to displace the same in the other direction, a conduit for each cylinder to connect the same to said cylinder bore, said movable valve element being adapted to afford communication between all said conduits whenever the pressure in said principal delivery port exceeds a predetermined value.

5. A pump which comprises a pump casing, a plurality of cylinders inside said casing, a check valve ported piston associated with each said cylinder, means to cause said pistons to reciprocate in sequence within said cylinders. means to admit iiuid to said cylinders through said check valves, a collecting chamber communicating with all said cylinders and with a principal delivery port within said casing, means to conductuid delivered by said cylinders into said chamber, a cylinder bore inside said chamber, a movable valve element slidably engaging the wall of said cylinder bore, said movable valve element being subjected on one side to the pressure prevailing in said chamber, said pressure tending to displace said valve element in one direction, and being subjected on the other side to resilient means tending to displace the same in the other direction, a conduit for each cylinder to connect the same to said cylinder bore, an auxiliary delivery port within said casing, a conduit to connect said auxiliary port to said cylinder bore, said movable valve element being adapted to aiord communication between all said ilrst-mentloned conduits andsaid last mentioned conduit:

6. A pump which comprises a pump casing, a plurality of cylinders inside said casing. a check valve ported piston associated with each said cylinder, means to cause said pistons to reciprocate in sequence within said cylinders, means to admit fluid to said cylinders through said check valve, a collecting chambercommunicating with all said cylinders, a collecting chamber communieating with all said cylinders and with a principal delivery port within said casing, means to conductv fluid delivered by said cylinders into said chamber, a cylinder bore inside said chamber and corinected to an auxiliary delivery port, a movable valve element slidably engaging the wall of said cylinder bore, said movable valve element being subjected on one side to the pressure prevailing in said chamber, said .pressure tending to displace said valve element in one direction, and being subjected on the other side to resilient means tending to displace the same in the other direction, two conduits for each cylinder to connect the same to said cylinder bore, one of said conduits being `adapted to be obstructed when said associated piston has completed part of its stroke. .and the other said conduit being adapted to be obstructed when said associated piston has completed part of its stroke, and the other said conduit being adapted to be obstructed when said associated piston has completed its i'ull inward stroke, said movable valve element being adapted to control the flow of fluid through said conduits and to afford communication through said first mentioned conduits whenever said pressure in said chamber exceeds a predetermined value and, upon further rise of the same pressure, to afford communication vthrough said second mentioned conduits.

7. A pump according to claim 1 in which said chamber and said valve means are adapted to act as an hydraulic accumulator having suilicient capacity to absorb a quantity of fluid as well as the usual pulsations of the pump without diverting iiuid to said fluid receiving means.

JEAN MERCIER.

' REFERENCES CITED The following references are ci' record in the tile oi' this patent:

UNITED STA'IFIS PATENTS Number Name Date 683,834 Beckneld Oct. 1, 1901 697,019 Richardson Apr. 8, 1902 1,135,414 Vincent Apr. 13, 1915 1,396,151 Wheeler Nov. 8, 1921 1,509,169 McFarland Sept. 23, 1924 1,910,581 Vickers May 23, 1933 1,971,601 Dilg Aug. 28, 1934 2,295,833 Deschamps Sept. 15, 1942 FCREIGN PATENTS Number Country Date 48,605 France 1938 468.122

Great Britain 1037 

